For example, in a vehicle such as an electric car or a hybrid car, a comparatively large electrical current flows through a device such as a power storage element, an inverter apparatus, or a motor. For this reason, there is a need to effectively dissipate the heat that is generated from wires when an electrical current is applied thereto. The technique disclosed in JP H8-235940A is known as addressing this issue.
In the technique described above, a heat dissipating coating material that has insulating properties and high thermal conductivity is provided on the outer peripheral surface of an insulating coating of the wires. Heat that is generated from the wires when an electrical current is applied thereto is transmitted from the insulating coating to the heat dissipating coating material, is effectively conducted through the heat dissipating coating material, and is effectively dissipated from the outer peripheral surface of the heat dissipating coating material to the outside thereof. Thus, the heat dissipating properties of the wires are improved.
JP H8-235940A is an example of prior art.
With the above configuration, heat that reaches the heat dissipating coating material from the wires via the insulating coating is dissipated from the heat dissipating coating material into the air. Because the thermal conductivity of air is comparatively low, the technique described above makes it difficult to sufficiently improve the heat dissipation properties of the wires.
Because the amount of heat generated by the wires decreases as the cross-sectional area of the wires increases in size, it is conceivable to increase the cross-sectional area of the wire in order to decrease the temperature rise value of the wire. However, this method cannot be employed because the wires increase in size.